Bit breaker



Dec. 3, 1940. M, D, CARLETON 2,223,600

' BIT BREAKER Filed oct. 12, 1959 [N VENTO/f?.

Patented Dec. 3, 1940 PATENT OFFICE nir BREAKER Michael D. Carleton, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Application October 12, 1939, Serial No. 299,091

Claims.

This invention relates to bit breakers, for use in rotary oil well drilling in removing rotary bits from drill collars.

In this art, when a drill bit is pulled out of the 5 hole to be changed, some means must be provided for holding the bit while the threaded coupling or drill collar which attaches it to the drill string is broken out and unscrewed. For this purpose an auxiliary bit-holding device is utilized which ts in the rotary table and supports the bit, at the same time holding it from rotation with respect to the rotary table. Heretofore such' devices have taken the form of breakout plates so designed that they received and engaged the bits at about the level of their cutters or cutting portions.

It is an object of this invention to provide a breakout plate which will engage the shank of the bit above its cutting portions and thus avoid injury to the cutting portions of the bits.

Another object is to provide such a bit breakout plate which will receive the lower large diameter cutting portions of a bit while the plate is supported by the rotary table, and which has parts that may then be brought into engagement with the smaller shank portion of the bit to hold it from rotation or to rotate it.

Further objects and features will become evident from the following disclosure when taken in connection with the accompanying drawing in which- Fig. 1 is a plan view of the device;

Fig. 2 is a cross-section taken along line 2-2 of Fig. 1:

Fig. 3 is a cross-section taken along line 3-3 of Fig. 1; and

Fig. 4 is a cross-section taken along line 4-4 of Fig. 1.

Referring to the drawing in detail, a plate I0, shaped to fit a rotary table, has an aperture II formed therein, of a size to receive a drill bit. Welded to the top of the plate, and depending below the aperture, is a U-shaped bar I2 adapted to support the end of the bit, shown in broken lines in Fig. 1.

Welded to the plate I0 on one side by means of rectangular members I3, I 3 is projecting lug I4, shaped to engage one of the channels in the side of the bit. A handle I5 is pivotedto this lug for lifting and handling plate I0.

On the other side of the aperture II, another pair of members I6, I6 are Welded onto the plate I0, and carry between them a lug Il hinged at its rear end to the members by a pin I8 securely welded between the members. This lug is of a (Cl. Z55- 1) thickness to extend downward to the bottom of the plate I0, and is shaped to nt into a gap I9 in .the plate and its yrear end shaped as shown in Fig. 4 to rest on the plate in horizontal position. 'I'he forward end of the lug I1 is beveled doWn- 5 wardly as shown at 20 in Fig. 4 to permit the lug to be more easily pushed downwardly when a bit is in the breaker. There is also a handle 2I on this lug to pull the lug out of engagement with a bit for removal, and also to cooperate with 10 handle I 5 in lifting the breaker.

In operation, the bit is raised clear of the rotary table and the bit breaker is lifted by the handles I5 and 2I and fitted into the top of the table. The bit is then lowered until it rests on 15 the bar I2 with its cutting portions of relatively large diameter below the plate, and the lug Il is pushed down until it is horizontal and ilts into one of the channels of the relatively small shank of the bit, and cooperates with lug I4 to hold the 20 bit from rotation with respect to the rotary table. Then, after the drill collar is unscewed from the bit, the lug I 'I may be raised and the bit removed from the device.

Although a preferred embodiment is disclosed 25 above, I do not wish to be limited thereto, but only by the scope of the appended claims.

I claim:

1. In a bit breaker, a plate, an aperture in said plate of a size to receive the cutting portions of a 30 drill bit, bit supporting means on said plate for supporting a bit in said aperture movable bit engaging means on the side of said aperture movable to engage the shank portion Aof a drill bit, and means for moving said bit engaging means 3D into and out of engagement with the shank of a bit.

2. In a bit breaker, a plate, an aperture in said plate of a size to receive the cutting portions of a drill bit, bit supporting means below said aperture, xed bit engaging means on one side of said aperture adapted to engage the shank portion of a drill bit, movable bit engaging means on the' other side of said aperture adapted to engage the r opposite side of the shank portion of a drill bit, and means formoving said last-mentioned means into and out of engagement with the shank of a bit.

3. In a bit breaker, a plate, an aperture in said 50 plate of a size to receive the cutting portion of a drill bit, bit supporting means below said aperture, a xed shank engaging lug on one side of said aperture, a hinged shank engaging lug lon the other side of said aperture, and means for 55 moving said hinged lug into and out of horizontal position for engaging the shank of a bit.

4. In a bit breaker, a plate, an aperture in said plate of a size to receive the cutting portion of a drill bit, a U-shaped bar under said aperture for supporting a bit, a fixed lug on one side of the aperture for engaging the shank of a. bit," a hinged lug on the other side of the aperture forengaging the shank of a bit, and a. handle for mo'ving said last-named lug into and out of horizontal, bit-engaging position.

5. In a. bit breaker. a plate, an aperture in said plate of a size to receive the cutting portion of a drill bit, a depending U -shaped bar below the 15 aperture for supporting a bit, a xed bit engagits lower end remote from its hinged mounting i0 for facilitating its engagement with the side of a bit, and means for raising this lug out of horizontal position. l, l

MICHAEL D. CARLETON. l5 I 

